<template>
  <div>Helloworld {{ a }}</div>
  <div class="box"></div>
  <div>
    <button @click="add">添加</button>
  </div>
</template>
<script>
export default {
  data() {
    return {
      a: 1
    }
  },
  methods: {
    add() {
      console.log(`helloworld`)
      this.a++
    }
  },
  watch: {
    a(newValue) {
      console.log(`helloworld`, newValue)
    }
  },
  mounted() {
    console.log(this.$route)
  }
}
</script>
<style lang="scss">
.box {
  width: 100px;
  height: 100px;
  border: 1px solid #000;
}
</style>
